How to remove a model which has been inserted in a Ros-enabled plugin??

I have a difficulty to remove a model during the simulation time. I have inserted this light point using InsertModelSDF() method in a callback function that is run every time data is published to ros topic.

I have tried to send a msg request to delete the model as you recommended it, but it couldn't recognize the light name and it gave me this when I run it:
Msg Waiting for master
Msg Connected to gazebo master @ http://127.0.0.1:11345
Msg Publicized address: 192.168.1.3
Error: No model name specified.

I also tried this with box model but it didnt work , I know that problem goes with recognizing the model name but I dont know how to do it even thouhgh I tried to get the model name in this way to delete the light